Direct Grignard pentylation of organotin-contaminated lard samples followed by capillary gas chromatography with flame photometric detection

During a recent investigation of the organotin-contaminated lard samples, a simple method was developed by direct Grignard pentylation of lard samples and capillary gas chromatography with flame photometric detection using qu artz surface-induced tin emission. Using HP-I capillary column with tempera ture programming and FPD detector, pentylated tri-, di-, monometyltin, dioc tyltin and Sn(IV) can be base-line separated and detected within 20 min. Th e analysis of pentylated tin compounds by GC-MS confirmed the existence of methyltins and inorganic tin in lard samples, which was agreeable with the results obtained by GC-FPD. The content of organotin compounds was calculat ed by internal standard method in which methyltripropyltin (MeSnPr3) acted as internal standard. The results showed that these samples were heavily co ntaminated with mg/g levers of dimethyltin, mu g/g levers of tri- and monom ethyltin. Among them, one sample contained mg/g level of dioctyltin and one contained a little of inorganic form of Sn(IV). The recoveries of tri-, di - and monomethyltin were 95.7%, 105.5% and 105.7%, respectively. (C) 2000 E lsevier Science B.V. All rights reserved.